JP2007312540A - Commutator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miniaturized commutator that prevents the bottom part of a slit groove from being broken. <P>SOLUTION: The commutator 10 allows a current fed from a brush 44 to flow in a coil 48 of an armature 40. The commutator 10 has a body 20 and a plurality of sliding-contact segments 30 arranged around a rotary shaft of the body 20 so as to be brought into sliding contact with the brush 44. Each slit groove 12 for separating the sliding-contact segments 30 adjacent to each other from each other is formed in the body 20. A reinforcing member 26 is inserted to a region on the counter-brush 44 side from the bottom face 12a of each slit groove 12 in the body 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a commutator that allows current supplied from a brush to flow through an armature coil.

  Patent Document 1 discloses a commutator according to the prior art. This commutator has a main body and a plurality of sliding contact segments arranged around the rotation axis of the main body. The main body is formed with a through-hole into which the rotation shaft of the armature is press-fitted and a slit groove that separates adjacent sliding contact segments. The slidable contact segment has a slidable contact surface with which the brush slidably contacts and a terminal to which one end of the armature coil is connected. When the commutator is attached to the armature, the rotary shaft of the armature is press-fitted into the through hole of the main body, and one end of the armature coil is connected to the terminal of the sliding contact segment. In a state where the armature is incorporated in the motor, the brush is in sliding contact with the sliding contact surface of the sliding contact segment. For this reason, when a current is supplied to the brush, the current flows to the armature coil via the sliding contact segment, and the motor rotates.

JP 2000-156955 A

In recent years, with the demand for smaller motors, the demand for smaller armatures has also increased. In particular, the space for arranging the motor may be limited in the axial direction of the motor, and it is desired to reduce the size of the motor in the axial direction. In order to miniaturize the motor in the axial direction, it is necessary to miniaturize the armature in the axial direction. In order to downsize the armature in the axial direction, the commutator attached to the rotating shaft of the armature must be downsized (thinned) in the axial direction.
However, when incorporating the commutator into the armature, there are a variety of factors such as press-fitting load when the rotary shaft of the armature is press-fitted into the through hole, and winding load when the armature coil is attached to the terminal of the sliding segment. A force is applied to the commutator. Since the commutator is formed with slit grooves, the thickness of the main body (thickness in the axial direction) is drastically reduced at the portion where the slit grooves are formed. For this reason, when a press-fit load, a winding load, or the like acts on the commutator, stress concentration occurs on the periphery of the bottom surface of the slit groove, and a significantly large stress acts on the periphery of the bottom surface of the slit groove. Therefore, when the commutator is simply reduced in size (thinned), there is a problem that a crack or the like is generated at the peripheral edge of the bottom surface of the slit groove and the commutator is damaged.

  Therefore, an object of the present invention is to provide a commutator that is not easily damaged even if the commutator is reduced in size in the axial direction.

The commutator according to the present invention includes a main body and a plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush. The main body is formed with a slit groove that separates adjacent sliding contact segments, and a reinforcing member is inserted in a region on the side opposite to the brush from the bottom surface of the slit groove of the main body.
In this commutator, a reinforcing member is inserted in a region on the side opposite to the brush from the bottom surface of the slit groove of the main body. For this reason, the bottom of the slit groove is reinforced by the reinforcing member. Therefore, even when a force such as a press-fit load or a winding load acts on the commutator, the commutator is prevented from being damaged.

In the commutator described above, the reinforcing member preferably makes a round around the rotation axis of the main body.
According to such a configuration, the bottom portion of the slit groove can be more suitably reinforced by the reinforcing member.

Moreover, this invention provides the novel commutator which can solve the said subject. The commutator includes a main body and a plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush. A slit groove is formed in the main body to isolate adjacent sliding contact segments. And while a main body has a laminated structure which laminated | stacked the several layer, the layer which forms the area | region of the bottom face vicinity including the bottom face of a slit groove | channel has high rigidity compared with another layer.
In this commutator, the layer forming the region in the vicinity of the bottom surface including the bottom surface of the slit groove has high rigidity. Therefore, even when a force such as a press-fitting load or a winding load is applied to the commutator, it is possible to prevent a crack from occurring at the peripheral edge of the bottom surface of the slit groove, thereby preventing the commutator from being damaged.

Moreover, this invention provides the novel commutator which can solve the said subject. The commutator includes a main body and a plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush. A slit groove is formed in the main body to isolate adjacent sliding contact segments. And while a main body has a laminated structure which laminated | stacked the several layer, the layer which forms the area | region of the vicinity containing the bottom face of a slit groove | channel has high elasticity compared with another layer.
In this commutator, the region in the vicinity of the bottom surface including the bottom surface of the slit groove is formed of a highly elastic layer. For this reason, even when the slit groove is distorted by the force acting on the commutator, a crack is hardly generated on the bottom surface of the slit groove. Therefore, a crack is generated on the bottom surface of the slit groove, and the commutator is prevented from being damaged starting from the crack.

Moreover, this invention provides the novel commutator which can solve the said subject. The commutator includes a main body and a plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush. The main body is formed with a through hole into which the rotary shaft of the armature is press-fitted and a slit groove that separates adjacent sliding contact segments. A portion of the inner wall of the through hole where the rotary shaft of the armature is press-fitted is formed by an elastic member.
In this commutator, a portion of the through hole into which the rotary shaft of the armature is press-fitted is formed by an elastic member. Therefore, when the rotary shaft is press-fitted into the through hole, the press-fitted portion (elastic member) is greatly deformed, and the stress acting on the bottom of the slit groove of the main body is reduced. This suppresses breakage of the commutator.

Moreover, this invention provides the novel commutator which can solve the said subject. The commutator includes a main body and a plurality of sliding segments arranged around the rotation axis of the main body and in sliding contact with the brush. The main body is formed with a through hole into which the rotating shaft of the armature is press-fitted, and a slit groove that isolates the adjacent sliding contact segment, and one of the plurality of slit grooves is formed in the entire axial direction of the main body. In position, it extends from the through hole to the outer peripheral surface of the main body.
This commutator reduces the stress acting on the bottom of the slit groove of the main body because the main body can be greatly deformed when a pressure input or the like when the rotary shaft of the armature is pressed into the through hole acts on the main body. be able to. This suppresses breakage of the commutator.

The commutator described above preferably has a curved bottom surface of the slit groove.
According to such a configuration, stress concentration on the periphery of the bottom surface of the slit groove is alleviated, and cracks are less likely to occur on the bottom surface of the slit groove. Therefore, a crack is generated on the bottom surface of the slit groove, and the commutator is prevented from being damaged starting from the crack.

The commutator of the present invention described above can be suitably used for a fuel pump. This fuel pump includes a pump unit and a motor unit, and the motor unit includes any of the commutators of the present invention described above.
According to such a configuration, a small and highly reliable fuel pump can be configured.

(First embodiment)
A commutator according to a first embodiment of the present invention will be described with reference to the drawings. The commutator 10 of the first embodiment is used by being incorporated in a fuel pump 60 as shown in FIG. First, the fuel pump 60 will be briefly described. The fuel pump 60 is installed in a fuel tank of an automobile or the like, and is used to supply fuel in the fuel tank to the engine. The fuel pump 60 includes a pump unit 62 and a motor unit 64.

As shown in FIG. 12, the motor unit 64 has an armature 40. The armature 40 includes a shaft 42, a laminated core 43 fixed to the shaft 42, a coil 48 wound around the laminated core 43, and the commutator 10 to which an end of the coil 48 is connected. Yes. The shaft 42 is rotatably supported in the motor unit 64. A permanent magnet 74 is fixed inside the housing 72 so as to surround the armature 40. When a current flows through the coil 48 via the brush 44 and the commutator 10, the armature 40 rotates.
The pump unit 62 includes an impeller 68 and a pump casing 69 that houses the impeller 68. The impeller 68 is engaged with the shaft 42 and is rotatable with the shaft 42. The pump casing 69 is formed with a fuel inlet 70a, a pump passage 71, and a fuel outlet 70b.

  When current is supplied to the brush 44 of the fuel pump 60, current flows through the coil 48 via the brush 44 and the commutator 10. As a result, the armature 40 rotates and the shaft 42 of the armature 40 also rotates. When the shaft 42 rotates, the impeller 68 rotates. When the impeller 68 rotates in the pump casing 69, fuel is sucked into the pump portion 62 from the fuel suction port 70a. The fuel sucked into the pump unit 62 is increased in pressure while flowing through the pump flow path 71 and sent out to the motor unit 64 from the fuel discharge port 70b. The fuel sent to the motor unit 64 flows through the motor unit 64 and is discharged from the fuel discharge port 66.

  Next, the commutator 10 will be described in detail. As shown in FIGS. 1 and 2, the commutator 10 includes a substantially disc-shaped main body 20 and eight segments 30 disposed on the main body 20.

The main body 20 is formed of an insulating resin. A through hole 22 is formed in the center of the main body 20. As shown in FIG. 3, the inner wall of the through-hole 22 is formed with a press-fit surface 22a and a large-diameter surface 22b having a larger inner diameter than the press-fit surface 22a. Eight segments 30 are fixed around the through hole 22 on the upper surface of the main body 20.
A slit groove 12 is formed in the main body 20. As shown in FIG. 1, the slit grooves 12 are formed radially at equal intervals around the through hole 22. A segment 30 is disposed between the adjacent slit grooves 12. Adjacent segments 30 are isolated by the slit grooves 12 and are electrically insulated. The slit groove 12 extends downward from the upper surface of the main body 20, and its bottom surface 12 a is located near the center of the main body 20. In the portion where the slit groove 12 is formed, the axial thickness of the main body 20 is reduced.
As shown in FIGS. 1 and 3, a reinforcing material 26 is inserted in the main body 20. The reinforcing material 26 is a ring-shaped metal plate (see FIG. 1) and has higher rigidity than the other part (resin part) of the main body 20. The reinforcing material 26 is disposed concentrically with the axis of the main body 20 in a region below the bottom surface 12 a of each slit groove 12. As shown in FIG. 3, the upper surface of the reinforcing member 26 is exposed on the surface of the main body 20, and forms a part of the bottom surface 12 a of the slit groove 12.

As shown in FIG. 3, each segment 30 includes a metal segment 32 and a carbon segment 36 fixed on the metal segment 32.
The metal segment 32 has a fixed portion 32a fixed to the main body 20 and a terminal portion 32b connected to the fixed portion 32a. The fixing portion 32a is formed in a substantially fan shape obtained by dividing a ring-shaped plate into eight equal parts. The lower surface of the fixed portion 32 a is fixed to the main body 20. The base end portion of the terminal portion 32b is bent from the fixing portion 32a and extends downward, and the tip thereof is bent outward and protrudes outward from the outer peripheral surface of the main body 20.
The carbon segment 36 has a substantially sector shape corresponding to the fixing portion 32a of the metal segment 32, and has high conductivity. The lower surface of the carbon segment 36 is fixed to the upper surface of the fixing portion 32 a of the metal segment 32. As a result, the carbon segment 36 is electrically connected to the metal segment 32. Further, the upper surface of the carbon segment 36 is a flat brush sliding contact surface 36 a for sliding contact with the brush 44.

  In order to manufacture the commutator 10 described above, for example, first, a carbon annular body in which the carbon segments 36 are annularly connected is fixed to a metal annular body in which the metal segments 32 are annularly connected. Then, the assembly and the reinforcing material are housed in a mold, and then the main body 20 is formed by injecting resin into the mold. Then, the obtained molded product is slitted to divide the assembly into eight segments 30. In this way, the commutator 10 can be manufactured.

The commutator 10 described above is fixed to the shaft 42 of the armature 40. That is, as shown in FIG. 4, the shaft 42 is press-fitted into the press-fitting surface 22 a of the through hole 22 of the commutator 10. When the shaft 42 is press-fitted into the press-fitting surface 22 a, a compressive force acts on the press-fitting surface 22 a of the through hole 22 from the shaft 42, and stress is generated in the main body 20. At this time, since the slit groove 12 is formed in the main body 20, a large stress is generated at the periphery of the bottom surface 12a of the slit groove 12 due to the stress concentration.
Further, when the commutator 10 is fixed to the shaft 42, the coil 48 of the armature 40 is wound and fixed around the terminal portion 32 b of the metal segment 32. Thereby, the brush 44 is electrically connected to the coil 48 via the carbon segment 36 and the metal segment 32. Even when the coil 48 is wound around the terminal portion 32 b of the metal segment 32, the winding load of the coil 48 acts on the main body 20 of the commutator 10. When a winding load acts on the main body 20, a stress is generated in the main body 20, and a large stress is generated on the periphery of the bottom surface 12 a of the slit groove 12 due to the stress concentration.
However, in the commutator 10 of the present embodiment, the reinforcing material 26 is inserted into the main body 20, and the vicinity of the bottom surface 12 a of the slit groove 12 is reinforced. Therefore, even if stress concentration occurs on the periphery of the bottom surface 12 a of the slit groove 12, this suppresses deformation in the vicinity of the bottom surface 12 a of the main body 20 and prevents damage to the main body 20.
In the above-described embodiment, a part of the bottom surface 12a of the slit groove 12 is formed by the upper surface of the reinforcing material 26. However, as shown in FIG. (That is, the reinforcing material 26 is insert-molded so that the upper surface of the reinforcing material 26 is higher than the bottom surface 12a of the slit groove 12, and a part of the reinforcing material 26 is processed by slit processing. The bottom surface 12a and the side surface of the slit groove 12 may be formed by the reinforcing material 26). Further, as shown in FIG. 16, the reinforcing material 26 may be arranged separately from the slit groove 12. Even if the reinforcing material is arranged in this manner, deformation in the vicinity of the bottom surface of the slit groove of the main body can be suppressed.

(Second Embodiment)
Next, the commutator 110 of the second embodiment will be described. In addition, the description which overlaps with 1st Embodiment is abbreviate | omitted or simplified (it is the same also about all the following embodiments).

  Similarly to the commutator 10 of the first embodiment, the commutator 110 of the second embodiment is used by being incorporated in a fuel pump. As shown in FIG. 5, the commutator 110 has a main body 120 and eight segments 130. Each segment 130 is isolated by a slit groove 112 formed in the main body 120 as in the first embodiment.

  The main body 120 is formed in substantially the same manner as the main body 20 of the first embodiment. However, no reinforcing material is inserted in the main body 120. The main body 120 includes an upper layer 150 that forms the bottom surface 112 a and side surfaces of the slit groove 112, and a lower layer 152 that forms the press-fit surface 122 a of the through hole 122. The upper layer 150 and the lower layer 152 are each formed of a resin, and the upper layer 150 has higher rigidity than the lower layer 152.

As described above, in the commutator 110, the bottom surface 112a of the slit groove 112 is formed by the upper layer 150 having high rigidity. Therefore, even when stress concentrates on the periphery of the bottom surface 112a of the slit groove 112, the occurrence of cracks in the periphery of the bottom surface 112a is suppressed, and the commutator 110 is prevented from being damaged.
A highly rigid resin usually has poor fluidity and poor moldability during molding. However, in the commutator 110, only the upper layer 150 is formed of a highly rigid resin, and the lower layer 152 is formed of a resin having lower rigidity than the upper layer 150 and having good moldability. Therefore, the lower layer 152 can be finished in a precise shape, and the press-fitting surface 122a of the through hole 122 can be formed with high accuracy.

(Third embodiment)
Next, the commutator of the third embodiment will be described. Similarly to the commutator 10 of the first embodiment, the commutator 210 of the third embodiment is used by being incorporated in a fuel pump. As shown in FIG. 6, the commutator 210 has a main body 220 and eight segments 230. Each segment 230 is isolated by a slit groove 212 formed in the main body 220.

  The main body 220 is formed in substantially the same manner as the main body 20 of the first embodiment. However, the reinforcing material is not inserted into the main body 220. Instead, a sleeve 223 is inserted into the main body 220. The sleeve 223 is made of an elastic material and has a higher elastic modulus than the main body 220 (resin). The sleeve 223 is disposed coaxially with the rotation axis of the main body 220, and the inner peripheral surface 223 a is a part of the through hole 222. As shown in FIG. 7, the inner peripheral surface 223 a of the sleeve 223 is formed in a circular shape, and the inner diameter thereof is smaller than the other portion 222 b of the through hole 222. Therefore, when the armature shaft is press-fitted into the through-hole 222, the shaft is press-fitted into the inner peripheral surface 223a of the sleeve 223. On the other hand, the outer peripheral surface 223b of the sleeve 223 is formed in an octagon. This prevents the sleeve 223 from rotating about the axis relative to the main body 220.

In the commutator 210 of the third embodiment, the sleeve 223 into which the armature shaft is press-fitted has a higher elastic modulus than the main body 220. For this reason, when the armature shaft is press-fitted into the through-hole 222, the sleeve 223 is deformed according to the pressure acting from the shaft, and the pressure from the shaft is distributed and transmitted to the main body 220. Therefore, the stress acting on the main body 220 is prevented from locally increasing. Thereby, damage to commutator 210 is prevented.
In addition, the shape of the outer peripheral surface of the sleeve 223 can be various shapes other than FIG. 7 (for example, FIG. 13).

(Fourth embodiment)
Next, the commutator of the fourth embodiment will be described. Similarly to the commutator 10 of the first embodiment, the commutator 310 of the fourth embodiment is used by being incorporated in a fuel pump. As shown in FIG. 8, the commutator 310 has a main body 320 and eight segments 330. Each segment 330 is isolated by a slit groove 312 formed in the main body 320.

  The main body 320 is formed in substantially the same manner as the main body 20 of the first embodiment. However, no reinforcing material is inserted into the main body 320. The main body 320 includes an upper layer 350 that forms the bottom surface 312 a and side surfaces of the slit groove 312, and a lower layer 352 that is formed below the upper layer 350. The upper layer 350 and the lower layer 352 are each formed of a resin material, and the upper layer 350 has a higher elastic modulus than the lower layer 352. Moreover, as shown in FIG. 9, the bottom face 312a of each slit groove 312 formed in the main body 320 is formed in a concave shape, and the cross section is semicircular.

As described above, in the commutator 310, the bottom surface 312a and the side surface of the slit groove 312 are formed by the upper layer 350 having a high elastic modulus. Since the upper layer 350 has a high elastic modulus, when a force is applied to the main body 320, the periphery of the bottom surface 312a of the slit groove 312 is elastically deformed, and excessive stress is prevented from being generated. Therefore, cracks are prevented from occurring at the periphery of the bottom surface 312a of the slit groove 312 and damage to the commutator 310 is prevented.
Further, in the commutator 310, the bottom surface 312 a of the slit groove 312 is formed in a semicircular shape, thereby relieving stress concentration on the periphery of the bottom surface 312 a of the slit groove 312. Therefore, it is possible to suppress the occurrence of cracks on the bottom surface 312a of the slit groove 312 and to prevent the commutator from being damaged. In addition, the shape of the bottom face 312a of the slit groove 312 can take various shapes. For example, a shape as shown in FIG. 14 can also be used, whereby stress concentration on the periphery of the bottom surface 312a of the slit groove 312 can be reduced. In the first to third embodiments described above, the stress concentration on the peripheral edge of the bottom surface of the slit groove can be alleviated by forming the bottom surface of the slit groove in a curved shape.

(Fifth embodiment)
Next, a commutator according to a fifth embodiment will be described. Like the commutator 10 of the first embodiment, the commutator 410 of the fifth embodiment is also used by being incorporated in a fuel pump. As shown in FIG. 10, the commutator 410 has a main body 420 and eight segments 430.

  The main body 420 is formed in substantially the same manner as the main body 20 of the first embodiment. However, no reinforcing material is inserted into the main body 420. The main body 420 is formed with slit grooves 412 that separate the segments 430. One slit groove 412a among the slit grooves 412 extends from the through hole 422 to the outer peripheral surface of the main body 420 at all positions in the axial direction of the main body, as shown in FIG. That is, one side surface 412b and the other side surface 412c of the slit groove 412a are completely separated. Thereby, the main body 420 is substantially C-shaped when viewed from the axial direction.

As described above, in the commutator 410, the slit groove 412 a extends from the through hole 422 to the outer peripheral surface of the main body 420 at all positions in the axial direction of the main body 420. Therefore, when the shaft is press-fitted into the through hole 422 of the main body 420, the main body 420 can be relatively deformed. Accordingly, it is possible to suppress the generation of a large stress in the main body 420 when the shaft is press-fitted, and it is possible to prevent the main body 420 from being damaged.
Also in the fifth embodiment, the stress concentration on the peripheral edge of the bottom surface of the slit groove 412 can be alleviated by forming the bottom surface of the slit groove 412 except the slit groove 412a in a curved shape as in the fourth embodiment. it can.

  As described above, according to the commutators of the first to fifth embodiments, even if the commutator is thinned in the axial direction, the commutator can be prevented from being damaged. Moreover, by using such a commutator for the fuel pump, the armature can be reduced in the axial direction, and thus the fuel pump can be reduced in the axial direction.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

The top view of commutator 10 of a 1st embodiment. The side view of the commutator 10 of 1st Embodiment. III-III sectional view taken on the line of FIG. FIG. 3 is a layout view when the commutator 10 of the first embodiment is attached to the fuel pump 60. Sectional drawing of the commutator 110 of 2nd Embodiment. Sectional drawing of the commutator 210 of 3rd Embodiment. VII-VII line sectional drawing of FIG. Sectional drawing of the commutator 310 of 4th Embodiment. Sectional drawing of the slit groove 312 of the commutator 310 of 4th Embodiment. The top view of the commutator 410 of 5th Embodiment. XI-XI sectional view taken on the line of FIG. FIG. 3 is a schematic sectional view of a fuel pump 60. Cross-sectional view of another form of commutator sleeve Cross-sectional view of bottom surface of slit groove of commutator of other form Cross-sectional view of another form of commutator with reinforcing material inserted Cross-sectional view of another form of commutator with reinforcing material inserted

Explanation of symbols

10: Commutator 12: Slit groove 12a: Bottom surface 20: Main body 22: Through hole 22a: Press-fit surface 26: Reinforcement material 30: Segment 32: Metal segment 36: Carbon segment 40: Armature 42: Shaft 43: Laminated core 44: Brush 48: Coil 60: Fuel pump 62: Pump part 64: Motor part 68: Impeller 69: Pump casing 72: Housing 74: Permanent magnet 110: Commutator 112: Slit groove 120: Main body 122: Through hole 130: Segment 150: Upper layer 152: Lower layer 210: Commutator 212: Slit groove 220: Body 222: Through hole 223: Sleeve 230: Segment 310: Commutator 312: Slit groove 320: Body 330: Segment 350: Upper layer 352: Lower layer 410: Commutator 412 : Slit groove 412a: Slit groove 420: Body 4 2: through hole 430: Segment

Claims (8)

A commutator that allows current supplied from a brush to flow through an armature coil,
The body,
A plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush;
The main body is formed with slit grooves that isolate adjacent sliding contact segments,
A commutator, wherein a reinforcing member is inserted in a region on the side opposite to the brush from the bottom surface of the slit groove of the main body.   The commutator according to claim 1, wherein the reinforcing member makes a round around the rotation axis of the main body. A commutator that allows current supplied from a brush to flow through an armature coil,
The body,
A plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush;
The main body is formed with slit grooves that isolate adjacent sliding contact segments,
A commutator, wherein the main body has a laminated structure in which a plurality of layers are laminated, and a layer forming a region in the vicinity of the bottom surface including the bottom surface of the slit groove has higher rigidity than other layers. A commutator that allows current supplied from a brush to flow through an armature coil,
The body,
A plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush;
The main body is formed with slit grooves that isolate adjacent sliding contact segments,
A commutator, wherein the main body has a laminated structure in which a plurality of layers are laminated, and a layer forming a region in the vicinity of the bottom surface including the bottom surface of the slit groove has higher elasticity than other layers. A commutator that allows current supplied from a brush to flow through an armature coil,
The body,
A plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush;
The main body is formed with a through hole into which the rotation shaft of the armature is press-fitted, and a slit groove that isolates the adjacent sliding contact segment,
A commutator characterized in that a portion of the inner wall of the through hole into which the rotary shaft of the armature is press-fitted is formed by an elastic member. A commutator that allows current supplied from a brush to flow through an armature coil,
The body,
A plurality of sliding contact segments disposed around the rotation axis of the main body and in sliding contact with the brush;
The main body is formed with a through hole into which the rotation shaft of the armature is press-fitted, and a slit groove that isolates the adjacent sliding contact segment,
One of the plurality of slit grooves extends from the through hole to the outer peripheral surface of the main body at all positions in the axial direction of the main body.   The commutator according to claim 1, wherein the bottom surface of the slit groove is formed in a curved surface shape.   The fuel pump provided with the pump part and the motor part, The fuel pump which has a commutator in any one of Claims 1-7 in a motor part.

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